Artificial limbs



Oct. 8, 1957 A. ANDERSEN ARTIFICIAL LIMBS Filed Feb. '7, 1956 FIG. 2.

FIG. 1.

United States Patent O ARTIFICIAL LIMBS Algot Andersen, Bergen, NorwayApplication February 7, 1956, Serial No. 564,076 1 Claim. (Cl. 3-41 Thisinvention relates to artificial limbs of the kind wherein the artificiallimb is secured to the limb stump of the wearer by the use of suction,the stump being received in a hollow space within the artificial limb,whereupon the lower end of said hollow space is evacuated by vacuumcreating means associated with the artificial limb.

It is an object of the present invention to obtain an artificial limbwhich may be secured to and adapted to the stump of the wearer in a mucheasier and more comfortable way than artificial limbs hithertofore knownin the art.

A further object of the invention is to obtain an artificial limb havinglighter weight than present artificial limbs, and assuring greatercomfort to the wearer than prior known artificial limbs of the statedkind.

A still further object of the invention is to obtain an artificial limbwherein the adaptation, and more specifically the shaping of outercontours of the artificial limb is not necessarily custom-made in eachindividual case;

in other Words, within certain limits at great part of the artificiallimb according to the present invention may be built up fromprefabricated elements needing only few adjustments to insure anexcellent fit.

An aspect of the present invention is that remodelling of the individualartificial limb may be accomplished without the necessity that thewearer must desist from his old artificial limb during the period ofreadaptation. At present, such remodelling operations take long time andnecessitate prolonged hospitalization.

According to the present invention, the artificial limb comprisesan-outer artificial limb casing, a limb-stump socket shaped to conformin the shape and size of the limb stump and adapted to be removablyreceived within said outer artificial limb casing, an air chamberdefined within said limb-stump socket by the walls of said socket andthe limb stump, means for creating a vacuum within said air chamber soas to secure said limb-stump socket to the stump by the use of suction,said vacuum creating means being arranged in the walls of said limbstump socket and spaced from said limb casing, and means for releasablylocking together said limb-stump socket and said outer limb casing,whereby said outer limb casing may be removed from said limb-stumpsocket while maintaining the latter secured to the stump by the use ofsuction.

Further objects and features of the invention are hereinafter referredto and claimed in the appended claim.

In order that the invention may be more clearly understood, referencewill now be made to the accompanying drawing which illustrate, by way ofexample, one form of limb suitable for a person having a leg amputationconsiderably above the knee joint, and in which:

Fig. 1 is a side view of the artificial limb according to the invention,with parts of the limb-stump socket and the outer casing broken away.

Fig. 2 shows the parts of Figure 1 in a section taken along the lineIIII of Figure l.

The artificial limb according to the invention com- 2,808,593 PatentedOct. 8, 1957 prises a limb-stump socket 1 having walls 2 and a bot-- tom3. The walls 2 are modelled exactly to conform with the individual shapeof the limb stump of the wearer, a close fitting being necessary atleast in the lower part of said socket, although a comfortable fit ispreferred in the upper part of said socket, too. In the bottom 3 asuction valve means 4 is arranged for creating a vacuum in the interiorof said socket after insertion of the stump, said suction valve means 4being of a construction well known in the art, which need not bediscussed to any greater detail in the present connection.

The wearer may secure said limb-stump socket to his stump by insertingthestump into the hollow interior of said socket, whereupon the wearermanipulates the vacuum creating valve means 4 to create a partial vacuumin the space defined by the bottom 3, the lower part of the walls 2, andthe lower part of the stump. Hereby, the socket is firmly secured to thestump by the vacuum created within said space. It is not at allnecessary thatthe outer shape of said socket conforms with the outershape of the limb to be substituted by the artificial limb; moreover, itis preferred to arrangesaid socket to afford maximum comfort, lightweight and excellent fit being paramount to this end.

Thus, it is intended that the wearer shall be able to leave said socketsecured to his limb stump also during periods of rest, i. e. when thereis no need for wearing an artificial limb, without any discomfort.

It is preferred to arrange the suction valve means 4 in the bottom 3 ofthe socket, although said valve means may also be arranged in the lowerpart of the walls. Usually, such suction creating valve means ismanipulated by pressing a central button inwardly and then releasingsaid pressure; a combination of a rubber disc and a return springcreates an evacuating action during the return stroke of said button.Because only small amounts of air can be evacuated in each stroke, thewearer has to press said button 'inwardly and release said pressurerepeatedly. By said valve means being arranged in the bottom of thesocket,rthe finger pressure against the button also ensures that thesocket receives the stump centrally. In prior known artificial limbs,the suction valve means were arranged excentrically with respect to thestump, whereby the finger pressure on the button tended to press theartificial limb out of its correct position with respect to the stump.

To the outer face of said socket a locking means part 5 is secured. Saidpart 5 co-operates with a counterpart 6 mounted onan artificial limbcasing 7 having an outer shape and size to conform with the limb to besubstituted by the artificial limb in question. The casing 7 is hollowand adapted to receive the limb-stump socket 1 in its hollow interior.The locking means part 5 and its counterpart 6 co-operate to form meansfor locking together the socket and the casing in a firm grip. Saidlocking means should be chosen to be easily fastened together and easilyreleased; in the present embodiment the part 5 is indicated to be ahook, and its counterpart 6 is a swingable eyelet, but any type of snapfastening devices known in the art to be able to lock together twotelescopically combined parts in a firm, releasable grip, may beemployed as locking means 5, 6.

It is preferred to use two diametrically opposed parts 5 and twosimilarly located counterparts 6, in order to ensure a firm grip At itslower end, the casing has a slot 8 and a bearing 9 for receiving a legpart 10 (see dotted lines in Fig. 1), as conventional in artificiallegs. Because these portions of the artificial limb according to theinvention are conventional, their construction need not be discussed toany further details.

As mentioned, the casing has an exterior shape and out- 3 linecorresponding to the amputated limb to be sub stituted by the artificiallimb, as exactly as possible 1n the manufacture of such artificiallimbs. The interior walls of said casing corresponds substantially totheouter shapev of the socket, but only to such extent as to prevent anyplay between the socket and the casing after locking said partstogether. ing a flange 11 at the upper end of the socket, towards whichthe upper edge 12 of the casing bears in a close engagement. shown) maybe arranged on either the outer face of the socket or the inner face ofthe casing in order to ensure, in co-operation with the interengagingflange 11 and edge 12, that the socket and the casing are lockedtogether without play by the locking means 5, 6.

In the manufacture of the artificial limb according to the presentinvention, the socket ,1 is preferably first modelled to itsrfinal shapeby heating and shaping a sheet of thermoplasticrmaterial. Thereupon, thecasing is shaped to enclose said socket and to correspond in shape andoutline to the artificial limb to be manufactured.

In Figure 2, it is indicated that the socket 1 is shaped to its finalshape, while the casing 7 has been shaped to an intermediate stage bybringing the edges of a sheet of thermoplastic material to overlap eachother at 13. These overlapping edges are secured to each other by meansof intermediate joints, such as nails 14. After having finished theshaping of said casing, the edges are cut to form abutting edges,preferably under an obtuse angle, whereupon these edges are securedtogether by welding or by a suitable adhesive. A finishing shapingoperation may comprise cementing thin sheets of the thermoplasticmaterial to areas to be thickened.

The socket 1 is preferably shaped initially in this way by firstoverlapping the edges and then cementing or welding the edges together,but in this case it should be ensured that the joint is airtight.

While the socket 1 must be built entirely different in each case, thecasing 7 may be prefabricated to the intermediate stage indicated inFigure 2, whereupon a final adjustment follows. Thus, it is onlynecessary during such final adjustment to have the socket 1 at hand.

In use, the wearer first secures the socket 1 to the stump by the use ofsuction. During periods of rest, said Such play is best prevented byarrange Eventually, mutually engaging parts (not l socket may be keptsecured to his stump, and the wearer may also secure said socket to'hisstump while sitting in his bed. Thereupon, the casing 7 is locked to thesocket by means of the cooperating locking means parts 5, 6.

A readjustment of the length of the artificial limb may easily bebrought about by readjusting the mutual positions of said parts, 5, 6.

The casing 7 is finally coloured in a suitable skin color, whereas it ispreferred to produce the socket from a suitable transparent plasticmaterial, in order to enable control of the position of the stump withinsaid socket when securing same to the stump.

In readjusting operations, it is easy to substitute the socket 1 byanother having a better fit.

What I claim is:

An artificial limb, comprising an outer artificial limb casing, alimb-stump socket shaped to conform in the shape and size of thelimb-stump and adapted to be removably received within said outerartificial limb casing, an air chamber defined within said limb-stumpsocket by the walls of said socket and the limb-stump, means forcreating a vacuum within said air chamber so as to secure saidlimb-stump socket to the stump by the use of suction, said vacuumcreating means being arranged in the walls of said limb-stump socket andspaced from said limb casing, a first locking means part arranged on thethigh face of said outer limb casing and a locking means counterpartarranged on the exterior face of said limb-stump socket, said first partand said counterpart forming together a snap fastening device forreleasably locking together said outer casing and said limb-stump socketin a firm grip substantially without play, whereby said outer limbcasing may be removed from said limb-stump socket while maintaining thelatter secured to the stump by the use of suction.

References Cited in the file of this patent UNITED STATES PATENTS980,457 Toles Ian. 3, 1911 1,586,015 Underwood May 25, 1926 FOREIGNPATENTS 662,502 Great Britain Dec. 5, 1951

